Due to the characteristics of light weight, small thickness, good portability and the like, LCD panels have been widely applied to various domestic televisions and portable electronic products. A typical LCD panel usually can only operate normally around the normal temperature, so that general indoor workplaces can meet the display requirement. However, as for cold climate areas or workplaces at an extremely low temperature, as liquid crystal molecules at the low temperature cannot be deflected properly, the LCD panel cannot operate normally.
In order to solve the problem of low-temperature display, the following methods have been proposed to achieve low-temperature liquid-crystal display:
1) An additional electrical heating element is arranged on the outside of the LCD panel, and heating to the display panel can be conducted through a control circuit. For instance, one layer of heating sleeve is attached on the back side of the whole LCD panel to heat the LCD panel, so that the LCD panel can display at a low temperature. However, as the electrical heating element has a big thickness and large weight in kilogram level, the structure will increase the overall thickness and the overall weight of the LCD panel.
2) A glass substrate, on which a indium tin oxide (ITO) transparent conductive film is deposited, is arranged between a backlight and a thin-film transistor (TFT) substrate, and the low-temperature display function can achieved by heating on the liquid crystal cell of the display panel with the transparent conductive film. However, as the ITO transparent conductive film has a poor heating effect, the heat which can be supplied to the liquid crystal cell may be very limited. In addition, as glass has poor heat conductibility, most heat produced by the ITO transparent conductive film is lost during the process of being transmitted to the liquid crystal cell via the heat transmission of the glass substrate. Therefore, by adoption of the structure, the heating effect of the LCD panel will be poor. Moreover, due to the glass substrate, the transmittance can be reduced and the weight of the LCD panel can be increased.
3) One layer of ITO film is deposited on the back side of the TFT substrate, and applying voltage to the ITO film to heat the display panel. By adoption of the method, the transmittance of the LCD panel will be reduced as well and the heating effect will be poor.